Bringin' Back the 21!

So a few years back, I bought a Madison Speakers Executioner X21, pictured below. Recently, It's been rotting away in the garage. Now that I have the full 1000w @ 8 ohms, to power that 4" aluminum voice coil, I want to resurrect it!

What's a good enclosure size?
It should be somewhere between 6 cf and 10 cf...

BTW, this is in no way meant to be a competitive system... this is a pro audio driver, and probably won't be loud (to the meter).

I'm thinking that I can show the true meaning of Street Beat for the next couple months, while I save for better street beat gear.

Now, back to the question. How much air space does a 21 need, to operate freely... say to 25 Hz

side note: It seems that Pyle bought out the remainder of these, and has rebranded them the PDW21250. These subs were asian no-brand parts assembled in Madison Speakers' warehouse before they became a strictly guitar/bass cab business.

Take a side shot.....looks like a warden basket???

not nearly as beastly as a Warden... but should boogie down low with authority, like they do.

I'll get pics in a few days, when I start building the monster box for this guy. thinkin about making a real "Bass Cube" 24"x24"x24" and installing swappable ports. That would allow some play time so I can learn which box directions/positions work well for big enclosures in the RAV.

It would also let me play around demoing subsonic sheeze, and swap to a comp port... for playing... well you know... Bass Cube! (in SB 3, 4 whatever)

So, after doing some box calculations... WinISD suggests an optimal enclosure of 13 cubic feet, tuned to 27 Hz. That's BIG. Then with external ports, it'll get even bigger. It'll be worth it, if the -3dB rolloff really is at 30 Hz (before cabin gain).

Trunk space available in the RAV (with no back seats):
Trunk width = 33"
Trunk length = 58"
Window Line Height = 24" in trunk, 20" on side doors

If I continue the recent trend of "monster CRX boxes" then we'd be talking about 24" x 24" front, with a depth of 46". Using my 3 4" aeros, they would need 8" more length, and that leaves 6" of space for the ports to flow. Seems fair enough. Let's do a solid model...